The present invention relates to a connector for connecting a duct used in, for example, various medical equipment, fluid infusion containers, and fluid feeding equipment.
A connector for connecting a duct is provided with a housing and a valve disc made of elastic material and connected to a connecting port of this housing, and is structured so as to be positively connected to the duct by this valve disc. The fluid flowing through the duct is fed to the interior of the connector.
The connector of such type is conventionally known from one disclosed in, for example, JP 9-108361 A.
This connector is provided with the valve disc having a bellows-like section (bellows section). When a duct is connected to the connector, the bellows section of the valve disc shrinks by means of the duct so that an end surface of the valve disc is pushed against the duct. Thus, the leakage of liquid from a slit of the valve disc is prevented.
However, in the conventional connector, when the duct is connected to the connector, the valve disc shrinks so that a flow path volume of the interior of the valve disc, i.e., the flow path volume of the connector is decreased in comparison with the case where the valve disc is closed, which causes various problems.
For example, in the case where the connector is connected to a catheter disposed in a blood vessel and used, the duct is connected to the connector, and an anticoagulant agent is infused into the catheter from the duct through the connector. Thereafter, when the duct is removed away from the connector, the bellows section of the valve disc is extended so that the flow path volume of the connector is increased. At this time, the blood is sucked into the catheter by a negative pressure.
Thus, the blood is coagulated to cause thrombi within the catheter so that the catheter is clogged and can not be used. For this reason, the catheter has to be removed. The number of operations is increased to impose a load to the patient.
An object of the present invention is to provide a connector having a fluid passage whose volume does not substantially vary with the opening/closing of a valve disc.
Such an object is attained by the present inventions (1) to (17) described below.
(1) A connector including: a substantially cylindrical connector main body having a fluid passage in its interior and opened at both ends; a valve disc disposed at one of opening ends of the connector main body and made of elastic material for opening the fluid passage within the connector main body upon the connection with a duct to be connected to the connector main body and closing upon the non-connection; and a substantially cylindrical connecting member disposed on the outer periphery of the connector main body on a side of the valve disc and coaxially with the connector main body to be movable in an axial direction of the connector main body.
(2) The connector according to the above-described item (1), in which the valve disc is opened by a pressure from the duct without the duct passing through the interior of the valve disc.
Normally, the duct has a taper outer peripheral surface that decreases gradually in a distal end direction. Also, the duct has a lure lock, and a flange is formed at an end section of the connecting member of the connector. If these are engaged with each other, it is possible to hold the connection more stably.
(3) The connector according to the above-described item (1) or (2), in which the duct is fit to an opening of the connecting member to thereby connect and hold the duct.
(4) The connector according to any one of the above-described items (1) to (3), further including biasing means for biasing the connecting member toward the connector main body.
(5) The connector according to the above-described item (4), in which the biasing means is composed of a spiral spring, a bellows spring or a stepwise spring.
(6) The connector according to any one of the above-described items (1) to (5), further including a position regulating means for regulating a position of the connecting member so as to expose a part of the valve disc in the vicinity of the connecting port at the time when the duct is not connected to the connecting port.
(7) The connector according to any one of the above-described items (1) to (6), in which the valve disc has a pressed section in which a slit section that is opened due to reception of the pressure from the duct is formed.
(8) In the connector according to the above-described item (7), in which the pressed section has a curved convex surface on at least one of a surface on a side with which a distal end surface of the duct contacts and a surface on its back side.
(9) The connector according to the above-described item (7), in which the pressed section has a curved concave surface on a surface of a side with which a distal end surface of the duct contacts.
(10) The connector according to any one of the above-described items (7) to (9), in which the surface on the back side on the side, with which the distal end surface of the duct contacts, of the pressed section is flat.
(11) The connector according to the above-described item (9), in which the pressed section has a curved convex surface on the surface on the back side on the side with which the distal end surface of the duct contacts.
(12) The connector according to the above-described item (7) or (8), in which the pressed section has a flat surface on the side with which the distal end surface of the duct contacts.
(13) The connector according to any one of the above-described items (1) to (6), in which the valve disc has a pressed section provided with a slit section opened upon the natural state and the shape of the valve disc is regulated by the connecting member upon the non-connection between the duct and the connector main body so that the slit section is closed.
(14) The connector according to the above-described item (13), in which a contour in plan view of the pressed section has a non-circular shape upon the natural state, and the shape of the valve disc is regulated by means of the connecting member to become substantially circular.
(15) The connector according to the above-described item (7), in which the pressed section has a first convex section on the side with which the distal end surface contacts.
(16) The connector according to the above-described item (15), in which the first convex section is formed into a substantially dome shape.
(17) The connector according to the above-described item (15) or (16), in which the pressed section has a second convex section projecting opposite the first convex section on the back side of the first convex section.
(18) The connector according to the above-described item (17), in which the second convex section is formed into a substantially hemispherical shape.
(19) The connector according to any one of the above-described items (1) to (18), in which the fluid passage distance of the connector main body defined between the contact surface between the duct and the valve disc disposed at one end of the connector main body and an opening on the other end does not substantially vary with the opening/closing of the valve disc before and after the connection between the duct and the connector main body.
(20) The connector according to any one of the above-described items (1) to (19), in which the volume of the fluid passage of the connector main body does not substantially vary before and after the connection between the duct and the connector main body.